Contour Enthusiasts Group Archives Forums Modifications Wheels & Tires Tire size difference (affect speedo.)

Although I knoe how t calculate it, it's a long-winded explaination. But, a look right down this list shows this topic:
http://www.contour.org/cgi-ubb/ultimatebb.cgi?ubb=get_topic&f=31&t=001375

Miata calc, know it, love it.